Unity Shader 学习笔记(十一) 混合纹理Shader实例

Unity Shader 学习笔记(十一) 混合纹理Shader实例

Shader "Custom/Blend" {
Properties {

_MainTint ("Diffuse Tint",Color) = (1,1,1,1)

_ColorA ("Terrain Color A",Color) = (1,1,1,1)
_ColorB ("Terrain Color B",Color) = (1,1,1,1)

_RTexture ("Red Channel Texture", 2D) = "" {}
_GTexture ("Green Channel Texture", 2D) = "" {}
_BTexture ("Blue Channel Texture", 2D) = "" {}
_ATexture ("Alpha Channel Texture", 2D) = "" {}

_BlendTex ("Blend Texture", 2D) = "" {}
}
SubShader {
Tags { "RenderType"="Opaque" }
LOD 200

CGPROGRAM
#pragma surface surf Lambert

float4 _MainTint;
float4 _ColorA;
float4 _ColorB;

sampler2D _RTexture;
sampler2D _GTexture;
sampler2D _BTexture;
sampler2D _ATexture;

sampler2D _BlendTex;

struct Input {
float2 uv_RTexture;
float2 uv_GTexture;
float2 uv_BTexture;
float2 uv_ATexture;
float2 uv_BlendTex;
};

void surf (Input IN, inout SurfaceOutput o) {

float4 rTexData = tex2D(_RTexture,IN.uv_RTexture);
float4 gTexData = tex2D(_GTexture,IN.uv_GTexture);
float4 bTexData = tex2D(_BTexture,IN.uv_BTexture);
float4 aTexData = tex2D(_ATexture,IN.uv_ATexture);
float4 blendData = tex2D(_BlendTex,IN.uv_BlendTex);

float4 finalColor;
//根据blendData.g 将 RTexture 和 GTexture 混合
finalColor = lerp(rTexData,gTexData,blendData.g);
//根据blendData.b 将 BTexture 混合
finalColor = lerp(finalColor,bTexData,blendData.b);
//根据blendData.a 将 ATexture 混合

finalColor = lerp(finalColor,aTexData,blendData.a);
//根据blendData.r 将 ColorA,ColorB 混合
float4 terrainLayers = lerp(_ColorA,_ColorB,blendData.r);
finalColor *= terrainLayers;

//防止越界 如果 x 小于 0 ，返回 0 ；如果 x 大于 1 ，返回 1 ；否则，返回 x
finalColor = saturate(finalColor);

o.Albedo = finalColor.rgb * _MainTint.rgb;
o.Alpha = finalColor.a;
}
ENDCG
}
FallBack "Diffuse"
}